This study will (a) describe the medical, genetic, and carrier knowledge and beliefs in a population of female relatives of individuals with severe type A hemophilia before and after the relatives accept or decline direct mutation carrier testing; (b) identify the percent of these women who accept the offer of free pre test counseling, testing, and followup genetic counseling and note their choice of one of three formats for pre test counseling - individually, with a spouse/partner, or in a group; and (c) describe their one and six months reactions to knowledge of personal carrier status and pre test counseling format on selected personal health behaviors and psychosocial variables, and describe nuclear and extended family communication patterns about hemophilia and carrier status. To accomplish this, the study will enroll 480 female relatives of individuals with severe hemophilia A who have been or are currently being followed at the University of North Carolina Comprehensive Hemophilia Diagnostic and Treatment Center who have a factor VIII gene mutation that can be detected by currently available methods. The study employs a longitudinal design. Participating female relatives will be interviewed before the pre test counseling and will complete self administered questionnaires (a) immediately after the pre test counseling and (b) at one and six months after receiving their test results and accepting or declining follow up genetic counseling. The study will employ logistic regression methods for clustered (nuclear and extended family) samples to identify the predictors of who accepts or rejects pre test counseling, carrier testing and follow-up genetic counseling. We will employ clustered statistical analytic techniques to analyze the impact of pre test counseling format and personal carrier knowledge on selected health behaviors, psychosocial variables, and intra familial communication patterns about hemophilia. There is very little information available on the acceptance of direct mutation carrier testing among the female relatives of individuals with hemophilia. There is virtually no published research on the individual behavioral and psychosocial sequelae to such testing nor on intra familial communication patterns about hemophilia and carrier status. The information to be collected in this study will help to close this gap in the research literature and will also be useful in the development of more empirically informed clinical and public health policies on direct mutation carrier testing for hemophilia A in particular and for carrier testing for X-linked disorders in general.